The number of tigers in India has risen for the first time in a decade, according to a new official census published in Delhi.

Campaigners and officials have hailed the news as proving that the big cat – which has suffered a 97% population decline in the past century – can still be saved.

In India, many tigers continue to be killed by poachers or die as a result of pressure on their natural habitats from the rapidly growing human population or environmental damaging caused by a lack of governance and the booming economy.

There are around 3,000 wild tigers in the world, of which around half live in India.

The census, being published tomorrow, is believed to put the total number of wild tigers in India at around 1,550 – 10% more than in 2008.

However, this may prove controversial because it has included the vast jungle and swamp areas of the Sunderbans, an estuary zone on the Bay of Bengal that had previously proved to difficult to properly survey.

Conservationists are also uncertain about the accuracy of the latest figures, claiming the methods used allowed the same tiger to be counted several times.

"A 10% increase is good news and very significant – but you can always fudge the figures if you want to, whatever counting method you use," MK Ranjitsinh, the chairman of the Wildlife Trust of India and one of India's best-known tiger campaigners, said.

In the 1970s, the Indian tiger population dropped to near 1,000. A major effort to establish reserves and increase protection of the animals resulted in numbers trebling by the end of the 1990s.

Indian tigers are a major draw for tourists, and attempts are currently being made to repopulate national parks that have seen all their tigers die, many through poaching to supply the growing demand for traditional medicines in China.

But problems remain. Many villages are still either within reserves or close to them, and local people are frequently attacked while collecting wood or walking to their fields.

Earlier this year, a tiger was shot dead near the Corbett National Park, in north-western India, after a series of fatal attacks on villagers. But it now appears the authorities may have targeted the wrong animal after a 45-year-old man was killed by a tiger two weeks ago.

"The human population continues to grow and that means reduction of prey, threats to the isolation of the tiger habitat and increasing danger of direct human-tiger conflict. We may have won a battle, but you have to win the war," Ranjitsinh said.